Without any other details, the aircraft in the background definitely looks like it's departing and on climbout. SID possibly, but likely flying a vector to join a SID.

The aircraft in the foreground has what looks like approach flaps down, but appears to be flying pretty low...as low or lower than most ILS minimums. If it was on an final approach and that low, the gear would be down by that point, and flaps much lower. Low pass of a runway or point? It's hard to say it's lining up for a localizer when you don't know a position.

Could also be in the pattern on a left crosswind leg off a parallel runway, or executing a missed approach.

The aircraft in the foreground is a development A350 (there's some kind of air data sensor thingy hanging from the tip of the vertical stabilizer). Maybe it's just doing a low pass for promotional photography purposes during a test flight with the aircraft in the background taking off from a different runway at the same airport. Not sure how ATC would describe that though...

I am sure, they asked you not for getting an accurate information about definite stage of flight but just to stimulate you for speaking English, for demonstrating it through your ideas. SOMETIMES, examiners are forced to speculate on the point